Find the chromosomal location of the Ah locus in the mouse. This will involve determining the Ah phenotypes of inbred strains or incipient inbred strains of M.m.molossinus and M.m.castaneus and creating backcrosses to strains of the opposite phenotypes. From these crosses, the segregation patterns of Ah will be determined with respect to the segregation of Amy-1(Chr 3), Apk(Chr 10), Gpt-1(Chr 15), Gdc-1(Chr 15), Np-1(Chr 14), and Got-1(Chr 19).